JPH0373668B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for improving color development of polyester fiber structures. Polyester fibers are widely used as materials for general clothing because of their excellent functionality and texture. However, it has a serious drawback that it is inferior in clarity, depth of color, and especially black color development compared to natural fibers such as wool and silk, and semi-synthetic fibers such as rayon and acetate. This is because polyester fibers are dyed with disperse dyes, which have a small molecular absorption coefficient among dyes and have poor visibility, and also because polyester fibers have a high refractive index of around 1.7, which has a large refractive index difference with air. This is due to the fact that the incident light is inhibited from penetrating into the fiber. Furthermore, since polyester fibers are manufactured using a melt-spinning method, their smooth surfaces promote specular reflection at the interface between the fibers and air, making it more difficult for incident light to penetrate. Conventionally, the coloring properties of these polyester fibers,
In order to improve the depth of color, a method has been proposed in which the fiber surface is coated with a low refractive index compound to reduce the difference in refractive index between air and fiber and reduce light reflection on the fiber surface. There are problems with its durability. On the other hand, roughening the fiber surface is considered to improve gloss and depth of color. For example, in Tokuko Sho 46-26887, the roughness of the fiber surface was
It is stated that a matte effect can be obtained by setting the thickness to about 0.03 to 1μ. However, simply removing the luster does not improve the color development or depth of the color.The reason is that the color of synthetic fibers dyed with titanium oxide appears pale and dull, or when exposed to high-temperature, high-concentration zinc chloride solutions. It is clear that the surface of polyester fibers treated with a typical polyester embrittling agent is rough and matte, but the color of the dyed product appears similarly pale. Recently, polyester fibers to which fine inorganic powder has been added have been subjected to hydrolytic weight loss treatment, and by utilizing the fact that hydrolytic weight loss progresses using the inorganic particles as cores,
A method of obtaining a fiber surface suitable for improving color development has been proposed. For example, an example of this is described in Japanese Patent Application Laid-Open No. 54-120728, in which the diameter is 80 μm.
A polymer component containing silica sol particles with a particle size of 1.0 m or less is melt-spun and subjected to alkali treatment to form random irregularities in the fiber axis direction. Although the rough surface obtained by this method can be controlled by adjusting the size and amount of the added fine particles, there is a limit to the improvement in color development. Moreover, because there is a difference in refractive index between inorganic particles and polyester fibers, the transparency of the fibers themselves decreases.
It also has the opposite effect to improving color development. In addition, there is a special technique in which polyester fiber structures are treated with a treatment bath containing an alkali metal or alkaline earth metal hydroxide and a quaternary ammonium salt compound to improve the texture and pill resistance. Kosho 44
It is publicly known from Japanese Patent Publication No. 47-29476 and Japanese Patent Publication No. 47-29476. However, the former is a method that efficiently performs alkali weight loss treatment, and the latter is a method that reduces only the fiber strength and elongation without substantially changing the thickness of the fiber. This method employs a quaternary ammonium salt compound, and has the disadvantage that color development cannot be improved. As a result of further studies on the prior art, the present inventors have discovered that when a specific amount of alkali is reduced in the presence of a specific amount of a quaternary ammonium salt compound, color development is significantly improved, and the present invention has been achieved. That is, the present invention has the following configuration. The method for improving the color development of polyester fiber structures of the present invention is to prepare a polyester fiber structure with an alkaline aqueous solution containing 3 to 30% of an alkali compound and 0.05 to 0.8% of a quaternary amnium compound based on the weight of the fiber. The present invention is characterized in that it is immersed at a temperature of 120° C. or higher and subjected to alkali weight loss of 50% or more of the theoretical weight loss rate to form horizontal concavities. This made it possible to provide a polyester fiber structure with good properties. The polyester fiber in the present invention has terephthalic acid or its ester-forming derivative as a dicarboxylic acid component, ethylene glycol, 1,4-
The target is fibers made of polyester whose glycol component is a glycol selected from butanediol or an ester-forming derivative thereof. A part of this dicarboxylic acid component is, for example, a monoalkali metal salt of 5-sulfoisophthalic acid, a dicarboxylic acid such as isophthalic acid, diphenylcarboxylic acid, naphthalene dicarboxylic acid, adipic acid, sebacic acid, dodecanedioic acid, or an ester thereof, p - Oxycarboxylic acids such as -oxybenzoic acid and p-β-oxyethoxybenzoic acid or esters thereof may be substituted, and a portion of the aliphatic or alicyclic glycol may be replaced with, for example, alkylene glycol having 2 to 10 carbon atoms, Glycols other than the main glycol component may be substituted, such as 1,4-cyclohexanedimethanol, 1,4-bis(β-oxyethoxy)benzene, bisglycol ether of bisphenol A, and polyalkylene glycol. Furthermore, it may be obtained by using a small proportion of a chain branching agent such as pentaerythritol, trimethylolpropane, trimellitic acid or trimesic acid, or a polymerization terminator such as monohydric polyalkylene oxide or phenylacetic acid. The raw material fiber for the polyester fiber of the present invention may be obtained by transesterifying dimethyl terephthalate with an aliphatic or alicyclic glycol, or
An aliphatic or alicyclic glycol ester of terephthalic acid and/or a low polymer thereof is synthesized by directly esterifying terephthalic acid with an aliphatic glycol or by adding ethylene oxide to terephthalic acid, and then The most widely used method is to subject the product to a polymerization reaction using a conventional method. Further, in synthesizing the polyester in accordance with the present invention, catalysts, color inhibitors, ether bond by-product inhibitors, antioxidants, flame retardants, etc. well known in the art can be appropriately used. A feature of the present invention is that the polyester fiber structure is subjected to alkali weight loss treatment to significantly improve color development. Such characteristics cannot be achieved even by performing a conventionally known alkali weight loss treatment, but can be achieved by alkali weight loss in the presence of a specific amount of a quaternary ammonium salt compound. Such quaternary ammonium salt compounds include:
For example, the following general formulas () and () can be mentioned, but there is no need to limit it to these. R ₁ : An alkyl group or alkenyl group having 8 or more carbon atoms. _R2 : Alkyl group, cycloalkyl group, aryl group, aralkyl group. R ₃ R ₄ : Alkyl group having 1 to 4 carbon atoms. R ₃ and R ₄ may form a ring. X: halogen, OH, R-OSO ₃ (R: alkyl group) R: Alkyl group having 12 to 18 carbon atoms, m+n is 2 to 30
Indicates the number contained in. However, it includes that either m or n is 0. Such compounds are commonly used as alkali weight loss accelerators, and examples include the following. Such quaternary ammonium salt compounds can be used alone or in combination of two or more. Polyester fibers have various excellent physical properties and are widely used as materials for general clothing, but it is well known that a major reason for their development is that their rigidity can be improved by alkali weight loss treatment. This makes it possible to use it for clothing, especially in the silk field. The alkali treatment is 30
It is common to immerse the polyester in a high-concentration alkali aqueous solution of ~100g/long for a long time, but in order to eliminate the various disadvantages caused by using a high-concentration alkali, the decomposition reaction between the polyester and the alkali is enhanced. In order to reduce the amount of alkali used as much as possible and shorten the processing time, alkali weight loss accelerators such as the above-mentioned compounds have been developed. For example, alkaline hydrolysis of polyester is shown with polyethylene terephthalate and caustic soda. It decomposes into sodium terephthalate and ethylene blycol and becomes water-soluble. Theoretically, caustic soda should be added to 1 mole of polyester monomer.
2 moles react, and the theoretical weight loss rate is shown by the following formula. Theoretical weight loss rate = 192 (1 for polyester fiber
Unit molecular weight)/2 x 40 (NaOH molecular weight) x NaOH concentration (%owf) Although the mechanism of action of this alkaline accelerator is not clear, it promotes the reaction between polyester and alkali, contributing almost all of the alkali used to the reaction. This makes it possible to reduce the amount of alkali used and shorten the alkali treatment time. For example, when polyethylene terephthalate and caustic soda are hydrolyzed by immersion at a high temperature of 130℃,
In a bath containing only caustic soda, it takes more than 4 hours of treatment time to reach the theoretical weight loss rate, whereas in a bath containing the accelerator and caustic soda, the theoretical weight loss rate is reached in about 1 hour, reducing the treatment time. It has an extremely significant feature of shortening. The amount of the compound used to achieve its purpose as an alkali weight loss accelerator is usually 1 to 20% by weight based on the polyester fiber. In the treatment of the present invention, the above-mentioned quaternary ammonium salt compound is added in an amount of 0.05 to 0.8% based on the weight of the fiber,
It is characterized by its use at extremely low concentrations.
That is, the present invention was able to obtain an extremely large effect of improving color development by employing a concentration that makes it difficult to achieve the purpose of an alkaline decomposition accelerator. That is, the feature of the present invention is that the fibers are formed with horizontal stripe-like recesses, that is, stripe-like recesses perpendicular to the fiber axis. This characteristic concave portion cannot be obtained by the above-mentioned conventional hand-improving treatment or anti-pilling treatment. Due to these characteristics, the coloring property of the quaternary ammonium salt compound is 0.1 to 0.5 based on the weight of the fiber.
It is further increased by setting it within the range of %. The coloring effect of the present invention is caused by the weight loss of the fiber structure, and in addition to the above-mentioned specific concentration conditions of the alkali compound and quaternary ammonium compound, temperature is also important. No horizontal concavities are formed. i.e.
Weight loss occurs at a temperature of 120°C or higher, preferably 130°C or higher. In particular, the amount of weight loss due to such treatment may be about the same as the weight loss rate of ordinary polyester fibers, but
In the present invention, it is particularly important to perform alkali weight loss of 50% or more, preferably 60% or more of the theoretical weight loss rate derived from the alkali concentration used, in order to form the above-mentioned horizontal grooves.Thus, the present invention In this case, the alkali weight loss itself is not important, but it is important to generate a horizontal concavity with a quaternary ammonium salt compound, and for this purpose, specific amounts of an alkali compound and a quaternary ammonium compound are used. , and how to reduce the amount by a specific amount under specific high temperature conditions is important. Here, the alkali compound used in the present invention is
For example, hydroxides of alkali metals such as caustic soda, or weak acid salts of alkali metals such as soda carbonate, etc.Although they may be used singly or in combination, hydroxides of alkali metals such as caustic soda are easy to calculate the theoretical weight loss rate. Preferably. The amount of the alkali compound used is 3 to 30% based on the weight of the fiber. The treatment of the present invention can be easily carried out using a jet dyeing machine or the like that is commonly used for dyeing processing. Furthermore, the method of the present invention can be effectively applied to polymers that improve color development by adding fine inorganic powder and forming irregularities on the fiber surface through alkali treatment, as described in JP-A-54-120728. In this case, in addition to the powder effect, the effects of the present invention are exhibited in a mutually beneficial manner, which is preferable. The method of the present invention will be explained below based on examples. Example 1 A jersey fabric made of 75 denier 36 filament polyester (manufactured by Toray Industries, Inc., molecular weight 192 per unit), highly twisted yarn (2300 T/M) was embossed with a washer according to a conventional method, and heat set at a temperature of 180°C. I went. This is then placed in a treatment bath at a bath ratio of 1:30 and a temperature of 130°C.
The immersion treatment was carried out using Caustic soda 7%owf (theoretical weight loss rate = 192 x 7/80 = 16.8%) Quaternary ammonium compound

[Table] After treatment, the remaining caustic soda was removed by washing with water. Next, each of these treated fabrics is
Dianix Black BG−FS 1:1 bath ratio containing 15% owf
Dye for 60 minutes at 130℃ in a dye bath of 30℃, reduce washing, wash with water,
After drying, a black dyed product was obtained. Alkali weight loss rate and
The L value of the dyed material is measured using a digital colorimeter (Suga Test Instruments).
Table 1 shows the results of the measurements. Here, the weight loss rate is the reduction in the weight of the fabric due to the alkali treatment, expressed as a percentage of the weight of the fabric before the alkali treatment. Here, the L value represents the visual density of a color, and the smaller the L value, the darker the color.

[Table] Here, the weight loss efficiency is expressed as a percentage by dividing the actually measured weight loss rate by the theoretical weight loss rate, and indicates how effectively the caustic soda used was used for weight loss effect. It is something. As is clear from Table 1, it is clear that the products according to the present invention have a remarkable effect of improving color development compared to the comparative example. In addition, in the method of the present invention (4) in Table 1, the weight was reduced in the same manner except that only the treatment bath temperature was changed to 110°C.
Stained. The constituent fibers of the obtained fabric did not have horizontal concavities, and the weight loss rate of the fabric was 12.5%.
The L value was 13.5. Next, in the method of the present invention (4) in Table 1, only the amount of caustic soda is 1% owf,
The weight was reduced using the same method except for 35% owf. The constituent fibers of the former fabric obtained have no horizontal concavities, and the weight loss rate of the fabric is 2.0.
%, and the L value was 13.8. Note that the fabric obtained by the latter method had horizontal concavities formed therein, but was thinner and thinner, so the L value was 13.8. However, the weight loss rate of this fabric was too high and the fibers were too thin, making it extremely weak and impractical. By the way, the L value of dyed blank (no weight loss) fibers after graining and heat setting is
It was 14.2. Example 2 Using the same heat-set resin as in Example 1, caustic soda 11% owf, The treatment time was varied in a treatment bath containing 0.5% OWF at 130°C to obtain weight loss treated fabrics with different weight loss rates. Next, the same treatment as in Example 1 was performed, and the weight loss rate,
Table 2 shows the weight loss efficiency and the L value of the black dyed fabric.

[Table] As is clear from Table 2, 50% of the theoretical weight loss rate
In the above weight loss, there was a particularly remarkable effect of improving color development, and the horizontal concavities were also relatively increased.

Claims (1)

[Claims] 1. A polyester fiber structure is immersed in an alkaline aqueous solution containing 3 to 30% of an alkali compound and 0.05 to 0.8% of a quaternary ammonium compound based on the weight of the fiber at a temperature of 120°C or higher. A method for improving the color development of a polyester fiber structure, which comprises applying alkali weight loss of 50% or more of the theoretical weight loss rate to form horizontal concavities. 2. The method for improving color development of a polyester fiber structure according to claim 1, wherein the quaternary ammonium compound is selected from compounds represented by the following general formula () or (). general formula R ₁ : An alkyl group or an alkenyl group having 8 or more carbon atoms. _R2 : Alkyl group, cycloalkyl group, aryl group, aralkyl group. R ₃ , R ₄ : Alkyl group having 1 to 4 carbon atoms. R ₃ and R ₄ may form a ring. X: halogen, OH, R- _OSO3 (R: alkyl group). R ₅ : Alkyl group having 12 to 18 carbon atoms, m+n is 2 to
Indicates the number included in 30. However, it includes that either m or n is 0.